Electrolytic lightning-arrester.



E. E. F. UREIGHTON. ELECTROLYTIC LIGHTNING ARRESTER. APPLIOATION FILED001. 11, 1907. RENEWED 00125, 1910.

Patented May 30, 1911.

I Ifivehtor: Elmer BF. Creighton,

Witnesses:

nnmnnn r. cnnrcn'ron. or SCHENECTADY, NEW YORK, 'ASSIGN on To GENERALELECTRIC COMPANY, A CORPORATION OF NEW YORK.-

v'r innc'rnomr rrc nrsnrnmcmmmsrnaz specificationot Letters Patent.Patented May 30, 1911.

Application filed October 11, 1907, Serial No. 3'.- )6,910. RenewedOctober 5, 1910. Serial No. 585,516.

To all whom it my concern:

' 6 Be it'known that I, Emunn E. F. Canton- TON, a citizen of the UnitedStates, residing at Schenectady, county of Schenectady, State of NewYork,- have invented certain'new' and useful Improvements inElectrolytic Lightning-Arresters, of which the following is aspecification.

This invention relates to devices for protecting hightension'transmission lines from. the destructive efiects of abnormallpotential, especially that due to ligtn'lng. On a transmission. line thelightning disturbanc'es may be divided into two classes advisable toplace an aluminum arrester in according tothe duration of. thedisturbancez'. e., whetherbrief or sustained; They may be termedrespectively transitory lightning and continuous lightning.- Aflightningar- 'rester of the aluminum type wears -out if subjected toa continuousflow oftcurrent, so. that fromrthefstandpoint of economy it is a circuitcontaining a normally open spark gap. Under these conditions, if alightning discharge istransitory it will spark across thegap, and if thegap is provided with arcextlnguishing burns, the dynamic arc 01- lowingthe lightning will rise thereon, break and open the circuit. But'if thelightning is continuous the arc will be continually reestablished asrapidly as it is extinguished. Inasmuch as the continual play of arcs upthe horns is in many cases objectionable, it is desirable to providemeans for closing the gap during such time as the continuous lightningis on the line.

The object of my invention is to provide a discharge path in which acurrent limiting device, such as an aluminum cell lightning arrester,has a spark-gap in series with it, and some current' responsive means,such as a time limit switch, which closes said gap when the lightning iscontinuous. The time element maybe secured by any suitable device, suchfor example, as a dash-pot or" a thermostat, but in any event it isdesigned to be unaffected by a transitory discharge across the gap. Inother words, it must not close the switch during the time that the firstone or two arcs are traveling to the tips of the horns. If, however,several dis charges follow in quick succession, the switch will close,and at the same time sound an alarm to notify the attendant.

In the accompanying drawing, Figure 1 is a diagrammatic representationof my invention, the time element being a dash-pot; and Fig. 2 showsanother embodiment in which the time element is thermostatic.

In both figures an aluminum cell lightning arrester 1 is connected toground at 2 and. to

line at 3 through a normally 0 en spark gap 4 provided witharc-extinguis ing horns 5. An electric alarm bell 6 is also included -inthe circuit. The aluminum cell arrester is the same as that disclosed inPatent;No. 923,024, granted to me May 25, 1909, and

need not be described in detail. v

The spark gap is provided with a time limit switch for closing it whenthe lightning becomes continuous. In Fig. 1 two contacts are arranged ina shunt around the gap, and a bridging contact 8 is mounted on a lever9. An elect-romagnet or solenoid 10 is placed in circuit 'withthealuminum cell,"and-its armature or movable core 11 is connected withsaid lever 9,.preferably by means of a spring.12 at a point adapted topass the fulcrum of the' lever when the core is attracted by thecoil'lO. The core carries a piston working ina dash-pot 14.

' Inasmu' h' as the solenoid 10.and the magnet coils in thebell 6introduce considerable inductance into" the circuit which interfereswith the' free discharge of small static charges, an aluminum cell 15 isshunted around the elect-romagnet 10 and a second aluminum cell 16 isplaced in shunt to the bell. These permit the high frequenc staticcharges to pass freely to groun Moreover, when the coil 10 becomesenergized by the dynamic current following a' lightning discharge ittends to move the pore,

and if the dischar eis continuous forseveral seconds, the retar ation ofthe dash-pot will finally be overcome. The instant the spring is carriedpast the fulcrum ofthe lever, the latter will'be suddenly moved and thecontact 8 will close the shunt around the gap. This stops theprocessionof arcs up the horns, and the discharge takes place through aclosed circuit. Thev ringing of the alarm bell notifies the stationattendant that there tention. The aluminum cell arrester is de signed tocarry the current for such length of time as may be necessary for. theattend- 'is a defective circuit which requires his atbars 17 18 ofdifferent materials having different coefficients of heat expansion.Thus the rod 17 maybe of brass and the rod 18 of iron, or evenof somenon-conducting material like Wood. 'The rods are pivoted together at oneend, and their other ends are pivotally attached to a latch 19, atdifferent points thereon. The latch upholds one end of a weighted leverwhose other arm is "connected, as by .ie link 21, with a pivotedswitch22, adapted to close the spark gap when the'lever 2O falls.

The passage of current for a given interval of time through the-rod 17will heat and expand it lengthwise sufliciently to .push the latch outfrom under the lever 20 and let it drop, as shown in dotted lines,thereby closing the switchand ringing the alarm 6; which in this case,also, may have the aluminum cell shunt 16.

In accordance with the provisions of the patent-statutes, Ihavedescribed the principle of operation of my invention-together with theapparatus which I now consider to represei'it the best embodimentthereof; but I desire to have itunderstood that the ap- 'paratus shownis only illustrative, and that a device for closing said gap co'mprrmg atime-limiting element. i

3. The combination with an aluminum cell lightning. arrester,'of aseries spark gap, a SWltClkfOl: closing said gap, and a device foroperating saidswitch comprising timeele ment means responsive onlyto acontinuous discharge of current.

1. The combination Wi'tlian aluminum cell lightning arrester, of aseries spark-gap provided with a horn arc-extinguisher,a switch f forclosing said gap, and'means for closing said switch only after thepassage of curr'ent across said gap for severa seconds.

'5. The combination with an aluminum cell lightning arrester, of analarindevice in 'cir cuit therewith, a spark-gap, and nieans :for

closing said spark gap in case the lightning is continuous. v

6. The combination with an electric emergency discharge device, of an alarm'device in circuit therewith and an aluminum condenser cell in shuntwith said alarm device.

7. A discharge path for abnormal poten i tial comprising a currentlimiting device-,0, spark gap in series with said dev ce,and'ai tomaticmeans for bridgingf said gap responsiveonly to sustained dischargethrough saidpath. i

8. A discharge path for abnormal potential comprising a current limitingdevice, an.

indicator which obstructs a free discharge a through said path and anelectrolytic con I denser connected in hunt to said indicator.

7 In witness whereof, I have hereunto set my hand this 10th day ofQctober,1 0' 7. ELMER ELF, onn ei 'ron;

